|Question 8Verbal

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Text
Superlubricity, the state of virtually no friction between materials, has desirable applications in many industries. For example, it can make aircraft engines more efficient. To produce a coating that achieves superlubricity, Chanaka Kumara and colleagues broke down carbon nanotubes into fragments of graphene to fully cover two surfaces that would rub together. Friction between pieces of graphene is generally extremely low, and when the researchers added a drop of oil as lubrication, that friction nearly vanished. This new coating may drastically lower friction-related energy costs.
According to the text, what happened when the researchers added oil to the surfaces covered in graphene fragments?
[Missing Choice A]
A
The low amount of friction between the surfaces became even lower.
B
Carbon nanotubes on the surfaces fractured into smaller pieces.
C
Friction between the surfaces did not noticeably change right away.
D
The surfaces became permanently bonded together and could no longer move.
A